基于霍尔元件的自行车的速度里程表的设计.doc

摘 要 随着居民生活水平的不断提高，自行车不再仅仅是普通的运输、代步的工具，而是成为人们娱乐、休闲、锻炼的首选。自行车的速度里程表能够满足人们最基本的需求，让人们能清楚地知道当前的速度、里程等物理量。本论文主要阐述一种基于霍尔元件的自行车的速度里程表的设计。以AT89C52单片机为核心，A44E霍尔传感器测转数，实现对自行车里程/速度的测量统计，采用24C02实现在系统掉电的时候保存里程信息，并能将自行车的里程数及速度用LED实时显示。文章详细介绍了自行车的速度里程表的硬件电路和软件设计。硬件部分利用霍尔元件将自行车每转一圈的脉冲数传入单片机系统，然后单片机系统将信号经过处理送显示。软件部分用汇编语言进行编程，采用模块化设计思想。该系统硬件电路简单，子程序具有通用性，完全符合设计要求。 关键词：里程/速度；霍尔元件；单片机；LED显示ABSTRACT With the developing of people’s life, the bicycle is not only the universal tool of transportation and substitute for walking, but becomes the first choice of entertainment and exercising. The bicycle mileage/speed can fulfill the basic need of people’s life, so that they can learn the speed and the mileage of the bicycle. In this paper, the bicycle mileage/speed design based on the Hall element is elaborated. By AT89C52 as kernel, using A44E Hall element to measure revolution, the measure and statistic are achieved. The range information is saved by 24C02 when the power is off, the bicycle speed can be displayed on LED. In this article, the hardware circuit and software design of bicycle mileage/speed instrument are introduced in detail. About the hardware, the pulse number is transmitted of one cycle of the bicycle into Single Chip Microcomputer system. Then the signal processed by Single Chip Microcomputer system is sent to display scream. About the software, in assemble language; the program is designed in the mode of modules. The system has simple hardware, common sub-program, and meets the demand of design. KEY WORDS: Mileage / speed; Hall element; Single chip microcomputer; LED 目 录 摘 要 I 第一章 绪 论 1 1.1课题简介 1 1.2 单片机发展趋势 1 1.3课题的主要任务及内容 3 第二章 系统总体方案设计 4 2.1设计总体思想 4 2.2硬件方案设计 6 2.3软件方案设计 8 第三章 硬件电路设计 10 3.1概述 10 3.2传感器及其测量系统 10 3.2.1霍尔传感器的测量原理 11 3.2.2集成开关型霍尔传感器 12 3.3单片机的原理及应用 13 3.3.1单片机原理简介 13 3.3.2单片机的引脚功能介绍 15 3.3.3单片机中断系统介绍 18 3.3.4单片机定时/计数功能介绍 20 3.4其他元器件的选择 21 3.4.1存储器的选择 21 3.4.2 触发器的选择 22 3.4.3 74LS244芯片的介绍 24 3.5单片机外围电路的设计 24 3.5.1时钟电路的设计 24 3.5.2复位电路的设计 26 3.5.3显示电路的设计 27 3